Historically, graphical language environments are use in specifying systems for simulation purposes. The specified system can be steady state system, with no variation in system parameters, or can be a dynamic system that is variable in nature in response to various stimuli. One such example of a dynamic system, as often modeled in a graphical language is an automotive driveline. External system parameters can be continuously varied within the simulation such that the modeled system is tested under the proposed operating conditions. For example, angular velocity of drive shafts and axels can be continuously varied, as well as forces and torques within the system. In light of this, a dynamic model can be created such that the proposed automotive driveline can be rigorously tested prior to actual fabrication and prototyping.
Traditional graphical language environments are comprised of a plurality of individual nodes. These nodes, when linked together, represent the system to be modeled. These nodes have associated with them a node labeling function that associates with each node a domain. Connected components of like labeled nodes are known as domain components. Additionally, associated with each domain is a domain parameterization that defines the parameters associated with each node as well as provides a means by which a graphical language user can modify the parameters of the domain. Modifying domain parameters allows a user to simulate alternative environments that the modeled system may operate in, and subsequently evaluate the results of these changes across the various nodes of the domain. Traditional graphical languages only provide for a single domain parameterization, such that parameters defined for use with the simulated model applies to all nodes of the simulated model. The defining of a set of parameters associated with a set of node is done globally from within the model environment during the creation of the model. For example, a user may initially define an angular velocity, for use with the automotive driveline example, when initially modeling the driveline. Using such an approach, traditional graphical languages allow for the propagation of this parameter across all nodes of the system which are subsequently attached to the node defining angular velocity, such that simulation and evaluation of the modeled system using this parameter is quickly accomplished.
Existing graphical languages, however do not provide a mechanism for allowing multiple parameters to be passed to predefined regions, comprises of like labeled nodes, of the simulated model environment in readily modified manner. Additionally, when modeling numerous systems, it is beneficial to allow a global variable property to propagate across a plurality of node wherein the value of the property is continually changing. Furthermore, existing graphical model environments do not provided for a mechanism wherein only a region of the graphical model receive a first external parameter and a second regions of the graphical model receives a second external parameter. In view of this, when working with a system that spans two or more external system parameters, wherein the propagation of a first parameter is only intended for a first region of the model and the propagation of a second parameter is only intended for a second region of the domain it becomes essential to split the system into two or more models, each using the proper external parameters. Using two graphical models, however, results in the inability graphically track and evaluate the effects of a change in first system parameters on the second system that does not share this parameter. The inherent limitations of using two distinct model environments are further compounded when working with variable time driven parameters.